Jennifer A. Johnson
Ohio State University
ABSTRACT
Carbon-Enhanced Metal-Poor (CEMP)Stars record the combination of AGB mass transfer and their own initial abundances on their surfaces. We find that CEMP stars with "normal" Li can be explained by mild amounts of mass transfer. The Li-poor stars, especially the ones with [C/Fe] < 1.5, require additional Li depletion from enhanced mixing or rotation. The F abundances in CEMP stars show a spread in [F/C+N], in accordance with theory. However, while the Na abundances are in good agreement with theoretical predictions for low-mass AGB stars, the quantitative predictions for F are a far worse match. These studies indicate the important tests of theory for both AGB and CEMP stars that come from probing the rarer light elements.